package com.yifan.utils;

import com.alibaba.fastjson.JSONObject;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;

public class UploadFile {

    // 上传文件存储目录
    private static final String UPLOAD_DIRECTORY = "upload";

    // 上传配置
    private static final int MEMORY_THRESHOLD = 1024 * 1024 * 1000; // 3MB
    private static final int MAX_FILE_SIZE = 1024 * 1024 * 1000; // 40MB
    private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 1000; // 50MB

    //@RequestMapping("/Upload")
    public void upload(HttpServletRequest request, HttpServletResponse response) {
        String savePath = "D:\\Upload File\\";
        // 检测是否为多媒体上传
        if (!ServletFileUpload.isMultipartContent(request)) {
            // 如果不是则停止
            PrintWriter writer = null;
            try {
                writer = response.getWriter();
            } catch (IOException e) {
                e.printStackTrace();
            }
            writer.println("Error: 表单必须包含 enctype=multipart/form-data");
            writer.flush();
            return;
        }

        // 配置上传参数
        DiskFileItemFactory factory = new DiskFileItemFactory();
        // 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中
        factory.setSizeThreshold(MEMORY_THRESHOLD);
        // 设置临时存储目录
        factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

        ServletFileUpload upload = new ServletFileUpload(factory);

        // 设置最大文件上传值
        upload.setFileSizeMax(MAX_FILE_SIZE);

        // 设置最大请求值 (包含文件和表单数据)
        upload.setSizeMax(MAX_REQUEST_SIZE);

        // 中文处理
        upload.setHeaderEncoding("UTF-8");

        // 构造临时路径来存储上传的文件
        // 这个路径相对当前应用的目录
        String uploadPath = request.getServletContext().getRealPath("./") + File.separator + UPLOAD_DIRECTORY;

        // 如果目录不存在则创建
        File uploadDir = new File(uploadPath);
        if (!uploadDir.exists()) {
            uploadDir.mkdir();
        }
        try {
            // 解析请求的内容提取文件数据
            @SuppressWarnings("unchecked")
            List<FileItem> formItems = upload.parseRequest(request);

            if (formItems != null && formItems.size() > 0) {
                // 迭代表单数据
                for (FileItem item : formItems) {
                    // 处理不在表单中的字段
                    if (!item.isFormField()) {
                        String filename = item.getName();
                        System.out.println(filename);
                        if (filename == null || filename.trim().equals("")) {
                            continue;
                        }
                        filename = filename.substring(filename.lastIndexOf("\\") + 1);
                        String fileExtName = filename.substring(filename.lastIndexOf(".") + 1);
                        System.out.println("上传的文件的扩展名是：" + fileExtName);
                        InputStream in = item.getInputStream();
                        String saveFilename = makeFileName(filename);
                        String realSavePath = makePath(saveFilename, savePath);
                        System.out.println("保存位置："+realSavePath);
                        FileOutputStream out = new FileOutputStream(realSavePath + "\\" + saveFilename);
                        byte buffer[] = new byte[1024];
                        int len = 0;
                        while ((len = in.read(buffer)) > 0) {
                            out.write(buffer, 0, len);
                        }
                        in.close();
                        // 关闭输出流
                        out.close();

                        Map<String, Object> map = new HashMap<String, Object>();
                        Map<String, Object> map2 = new HashMap<String, Object>();
                        map.put("code", 0); // 0表示上传成功
                        map.put("msg", "上传成功"); // 提示消息
// 						String newPath = "upload/" + fileName;
                        String newPath = "/upload/"+saveFilename;
                        map2.put("realsrc", realSavePath  + saveFilename);
                        map2.put("src", newPath);
                        map2.put("title", saveFilename);
                        map.put("data", map2);
                        map.put("url", newPath);
                        PrintWriter out2 = response.getWriter();
                        JSONObject json = new JSONObject();
                        System.out.println("map的信息："+map.toString());
                        String info = json.toJSONString(map);
                        out2.write(info);
                    }
                }
            }
        } catch (Exception ex) {
            request.setAttribute("message", "错误信息: " + ex.getMessage());
        }
    }

    private String makeFileName(String filename) {
        // 为防止文件覆盖的现象发生，要为上传文件产生一个唯一的文件名
        return UUID.randomUUID().toString() + "_" + filename;
    }

    private String makePath(String filename, String savePath) {
        // 构造新的保存目录
        String dir = savePath;
        System.out.println("保存目录："+dir);
        // File既可以代表文件也可以代表目录
        File file = new File(dir);
        // 如果目录不存在
        if (!file.exists()) {
            // 创建目录
            file.mkdirs();
        }
        return dir;
    }
}
